SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e43d8b795639c9c44785109b8d023505b6fa7af55d553b21e5707bbd34dc19d' 
  AND token = 'g3itf6T1q0uTbcAniiRxZXIt5oXZfqoVaCbHNHRTu80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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