SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e0c4bf2a1d159f391b81cd8dbf0ce13d992f3f743211aadb9f9aa651389ac6db' 
  AND token = 'dK1G8lr5joex9OQbFVLJkjMBDxh+nomfpkBS08+xjiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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