SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b02edef3225c2da1a4ac412365f95176fc25fdab946921454e25ab84efe4e55' 
  AND token = 'c42cl0vjKGx+of58Z8H4tfgaO+xxzVERtqd1pEQki4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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