SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa8d9e2e7a1879cdccf0c1f081d4b87047324b977be8f857026a5e40c4da350b' 
  AND token = 'K7xUTfS2L2OJb6VlmxEzy+iq1BWamkdUfpzApiGcbrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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