SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0d592348e6a967de246c95e0aa181a0f50e6464719f7fc5c945f26d24d9948e' 
  AND token = 'SUzczbso9jcIqs4YWWlLGtOF0+NnP9jPep4sviGgXY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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