SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bbad819885660b0ddb4593820a14c73846f5cf9f4235c0cb73a0847232f6332' 
  AND token = 'HQKNrN+K1yKxegxUq/mvHziX8xDhMY5n/PiRFmdM78Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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