SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3423cf6c6d9796cada7fd8f25e94337902adc727b031e758d2bc888f7579254c' 
  AND token = 'gXxi/A2vFooZdBPuM5nEL+wyzGqwCTLu4yMv4YYAf4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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