SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '188f0a7a978ed7ce93bcafdcfd0e1c998ec3351b6aed250fc6234b7243f9e31e' 
  AND token = 'E0gSde6FmPMCOiKzZeAw00Y+s3ftaXI7RJAaJQBtKiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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