SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e944488a63b071564fa53d7ddb386a8d14f3730276867ef3296cff221847fe58' 
  AND token = '9akKo6KoThB1zjzT5u8kvvtl7hjGQWA5/JTZL18jmAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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