SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a82bc2ed1db39d9393f076791c284368b145998efa17b9411a3b043fc8ed7183' 
  AND token = '7URYzMjpDEC5eRTfUKFFT15lDYAHkBCJ2ju+Dc0nHLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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