SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '587134654db4bf346265a4b682735bf1b199ca2ef708e4c7e600dfd26d9d5923' 
  AND token = 'CKF1CvNYWjrjyCUJrMgA59UeW3p7IpX3vh4Ejlnawhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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