SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ab6dcf989bccaad2caa49854f662313a8cb7fd5cae2beb200e8edda66b757a6' 
  AND token = 'D+91MU4NFQ9tz8RtZOEoW8d23vkq6MowWdwuMvJNyrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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