SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ef4ffadd8e620210d21ca226e9e825fa5e7e0932c27baff77f50ac1ddec5b54' 
  AND token = 'KJfQQHxGzfJMcNibghcVNGxhSf8meOlAroVc4HjWSaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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