SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '453fe8d8798c854dd79782e567fb908dba79d2fd696c44f0fef8e4dcab93b42c' 
  AND token = '+dWZWCkNhyDdpdlKdIrJLm7KXCLZpDYrC7OR/cUigZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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