SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ede47738597788c704ed0a1507b1b31ea73db90a9abbb33361d29238d4f04f06' 
  AND token = 'SQas7w8fYGCdtlei5dGXlnfS4JllygjnaOA0CuUgjjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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