SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '495b22ae14e9c6f5761ba319a2ae50b5b2239e30ff73c227dff44bfac89549d8' 
  AND token = 'QH1GJwcV+wt2JNt6mH0HZN/BqzRm6t6e0iKVdLjtmBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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