SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55ec19b7f407efc54385bab303da6b9c11b4ab07bdf16827652f676c969dee23' 
  AND token = '+RDWmubq+XvJgGpjIW+zw2Fvhs4pRYm5T6IpZNVTUhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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