SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '418aaeae503ad0938ba159ed46667af872669528b967e3db3c7f6b9a66d871a1' 
  AND token = '5Phl7xoWk5ZJz9mfaSwkjHRUUSzIDcHCsVXKcB4asqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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