SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e28f2a4ebfdf589155973c0c436a23bd0647709a8e81e1e0a100a6360c7dda72' 
  AND token = 'kIrlcfuQkW20sC9WcHEwxbowTqcGryADfcbb8zuEppE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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