SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28acb168ed90989b0ac9a136385ae61010570c9b0d51dbc77b04aebde592cc81' 
  AND token = 'iJ1+htbzkuazZJaiLDJ+gAZON4TEC8nFZeqQZ08vxmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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