SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edb1242ae925855b23f402a097a110b5db988a69df41cde9cb18fbf428afc66b' 
  AND token = 'pbFvkPh3bY/hmqxr5s1FRZMSYXaAwGsBd1M4lLPkRo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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