SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54ecf94cad385d86da265b5e8ed47667cdecb3fa801b18b8e8ec8ff5538fe7a2' 
  AND token = 'y4/UaGSCP5DDZMap6xwbSMTzgIfd445uWoTDNe0spVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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