SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '217a801191d905278262e84f5037958d797d928bfa0149c8aaedc626bf03aacd' 
  AND token = 'IEik3zZ3z3CPBeWTqrf3ZOPvd50XJpjZotxj58YLMTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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