SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bad51f783ddee8908dbf731f507f07b22af3aab10dbeb228ea64087d928d0e0c' 
  AND token = 'd1lTor1JpPNETwcVjguh7FRAyCiQskyTnWYymS6FbGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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