SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5983b8762bd31be273cd13a19fa424ed2422f19537956e8a1e0625f1c719130a' 
  AND token = 'nTqiUSqxz+pam34nHYWZ4iG5ZLrUK613kqPjWDTGudU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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