SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e52a2415b5da9dada9e97c7409527776528d6e7a2c69311bd6a87f24afcd3ce8' 
  AND token = 'bLxR6pcjNlxDeiXFio/nTvg9FH4EgH2JkQP0iiPR1PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}