SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '952371d42bc3e3914f5ae2b07204e51591fac9028eda85eeb20f5e12ae3a3ee4' 
  AND token = 'd1V95u/NPXIzYZQNf0C8vEz9z4EO7bs5KKGPRqHxp0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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