SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a65a9e188dbf78a6199dc2c9714de82a083e2a055b7feba1caad9d312c215796' 
  AND token = 'f/FPSOVLXFJ093ebWfZeATXOGmi3auQ9QiFihYSzGqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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