SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34306b76165763ee4cd889fc99c24375e231797c1b953cede0f0b6f8bba6db09' 
  AND token = 'PKWz1lU5G3IqXiVdEoBJMuxP/+TzH+CN9LYUR3ENLI4=' 
  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"
    }
  }
}