SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42251edb4ce06c7945579c730022c2a52cb0fe36f39eae8980e9ade18a084aa1' 
  AND token = 'Akmsff6QL9DDuB7IfD/uMgviarQSidyAIK2I6J6BjeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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