SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eec952a769407494e23dac577fd602581d279483b80ccb91600a820db6a2b28d' 
  AND token = 'smbIgyB/o8iuDnjwKiS+iia+meh55ifYw76BMrJ8lek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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