SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4fca757b87b89b4b10cefcd4290f0d7fa560ab23910f59a1c9ace5d3bc1e6ce' 
  AND token = 'pguVlx5/RbKWE1yNYkwiITgGo75CBropkqDKyv+vAus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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