SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cdc065118828bce8820d346969ee8bca8b917756b659589c5cc85b03a742bdd' 
  AND token = 'rIA0ORy7ptDXoESFvhSHYcooVNQdjmImxpMlQ2rvPM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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