SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b9850b517da513ed4f3166b741515f533ddd14e1a38a0752f95dbdd0d95b8d' 
  AND token = 'dMjpHksndqBcis+QGeBUvUUJFU1H6RyAUIKNjBwoWAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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