SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3e7b4b26092b14022c5553aaf93cd8c1d1ebc70b54c756a5948798b54824dbb' 
  AND token = '7svpDEFbZUdX4ZwDv4uzCOREoD7hE+bJ3xXrFtUBnZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}