SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5037fee650e87cf85aaea921049c8c8aa6d35643e4eb2a572a7aae6f196793f1' 
  AND token = 'k9xOkftpEzhQ277aM5FfY3a4LWcdzet8M4OmHo97iOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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