SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2cf51dd1aad4678766152bbeeefe23f54c4adc15e0c2e8fff1dc7a1e0b8b1cbc' 
  AND token = 'XB9pXqFDWgDGk3rYxVPCjRBQZpzHxHHqUJjKw5cc7YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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