SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65c3004233aff17b65b4bd6f7a4191301ffe7b224c96d3739d401908b9f8818c' 
  AND token = 'RSlgAc5nJZFoJGVrO+jnEQlHY/mbuN3zt/pK7iPB3Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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