SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '325b302b5717bb7fd348f90de7cd881186e55b9160b6636b2cd634c7ccc06ce7' 
  AND token = '5oimjMU88DuHmbrUFBVsQKGjkRfqzRJKEqd4nnxY2bQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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