SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fd7274bfd1a08dc609e058e33158af2e43d0d54d62eecd3ed7679aa79154eb7' 
  AND token = 'z4FfTNyFjD1b9HRiLRouMC6vwzL7z8R/E3AoycIdkb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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