SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79ccad29669ec998e30345b33a90fe8ee2cb62e0328b78ed6d5d33352f79e6ff' 
  AND token = 'jQrJti1ciOShLHXfrYwbSVm8/IiTBjcZ1C/WKxoNZMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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