SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1c8ff840151da0c4e2ba2eb4ee56a041a31b9192432de1026d767403c5cb850' 
  AND token = 'MZr6JmtRWhc7nmgxk3MUtpw16ryO7yqrQNse5TBLMiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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