SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '937c0438d32acc728d184b7c90eb9624c3f0f07d594d26063edb75d031e95eb0' 
  AND token = 'qppCrLlJS2shapcIX5DajBdegyH7BooUHLcY1KzX6Vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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