SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f44838214901347088787c69b6e7d79aa0620876548f9d75a65d58fb6d5cf061' 
  AND token = 'mosypF0uvacHZEV3SVRDQw3bpDGTT2t3HFEJUBii61s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}