SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb28c91ee9ae653a3d23c09777d665fe640a32660477b68dfa3cf071771ba9e7' 
  AND token = 'qc2P4fCSDmXwK2Ok1RVBBSwPE8LfVjyiQcfRouLfn60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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