SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1c9473134554413bbc72f025937fbf7354e805ca2e9f7e21e03787b9a63ef256' 
  AND token = 'DHnLX5PodimLNZZjNhqHyJvIUyga7y1GuHVfilzhlx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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