SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '88ad010f9df225ef98ed38a1391e36454965cb9e0578326f96c5c52b30b010d6' 
  AND token = '3WVYrJybc/Htk/qLlBj1b5a8tyWz0QAugAq0SqzGQuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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