SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0468ab3bb24432c6081f9a72625976be6442325a15a5a7056eeeb4f19909c71f' 
  AND token = '4t5vhUJ9FMmKGIuCAAPVcfzEAPlEZnS7wJrWxeyAkLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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