SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9ae778a726419c34c099ed1b4a2351874dde589938ad8fae0b7cfbd13b9cbba' 
  AND token = 'fSNWnb4SuUFz7ppndkXPBn50sBsLsCpnmro6PjnbC90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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