SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da7dea18051fecf4709be0a4a5a68d8ebfe20fbe99ff34c96fd3c188a5ba1a5c' 
  AND token = 'MvxcWTxqsSF6GoYpry98evSV58ithc3LQwPVrmZHPVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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