SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a51c10dcd0e81476b9f8645efc345526199ac19740404dd387e8c8e62494e61' 
  AND token = 'XUzW7ixsDx2zg6kH8OSsSd2NB5oycnb3TPT6EtG3FqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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