SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20c45842fcd09aec06d588d8ff257bde6855747d83a463c3a5da9c42983b64b4' 
  AND token = 'Th/58fX0SpU2pW1RUptIzo6Y/KpuzfvFqiHB+b2STT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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