SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61916e3c74d09304eb238fa9a23b934d8b781733694b3ed434f5fdff6610eeac' 
  AND token = 'LzvaXEpStnDsg6DwyCTNrnwl2qBzTMo/8eX6hdLn0FQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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