SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2f98051d01b63127526fce6d1addcaad0bf4fa88617b67d6062f74b2e98b775' 
  AND token = 'qfjiRA/IbIBGofklGgIthht4lJKtC+QbEyMWt5WVNsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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