SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c970375ed3c8cdaf617d0eda18749bfef2558fe0d8131bf81f3f71eb8e1b7b9' 
  AND token = 'PW1yiFqL5YCMgDtLrH4YiDf9LRjiEozQVbTsHNJmu04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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