SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45471ba8ee2fb34348049e4298371a7cad0c336e4e4e60ddfd30a3fd092dc32b' 
  AND token = 'AgfyhtUeSJQ5zClm+BIZbEMw5pxRfYmM203l4ONaZZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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