SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78d03f8603ef4fe14757bd527553902adc3c1dd0c4dfe1bd08ab0495bbf24fec' 
  AND token = 'SbD+Y2WqqqXrowCWssOurCkegcq9jxNZx9xMx5aKBJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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