SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12a608a8c8bc84ef8e70b764d880e5f05b944322599fea2e3216cabdecfe0641' 
  AND token = 'Xsz6OEQSwaLvBRl3FTbFtwkkVCpq1gOiDjMczlrJvJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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