SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34c59ccc75d251d8bc336faa5b3352f806d27bb08c0edafc5f9ce9b5fdd26081' 
  AND token = 'xXwFYcMGyxblXaLgmRfC4qvmUZEOrpgH2Ba9+qnuHpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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