SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a466ae4edcc33da3a76647e1f874a1c23670eb0d87dcdb979cedcc2734fd922' 
  AND token = 'Lksk4RehX8bz7NBG0T+ruxlLH3mYvC4LO8Ac/RKNCuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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