SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcb84bb90180b8c27c7745527b99db1fa521c469249f945b7368d5d86dafd963' 
  AND token = 'Xk8cMbAnpwdnpWgaGndVmbwdbRlvFzHybl6Ah07gqGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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