SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4292a51cc63a51f42fed8d012ce37d4c6ff0748920e0ffd5f151eb0b8b23ec6f' 
  AND token = 'M45dUhIAzsxQuMtK16b8YoUpyHLSEv9jvzQR7kfdB4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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