SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94b15113a2f5081e4896edabb9c31cacb7174716252dc944599ea7eed318e01f' 
  AND token = 'KHAdnlGL+gLoAWSufptOS5DJ0KocOxX4z/hG/m9bJrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}