SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0428879e4dbba14a74eb49c63f5b6dd481d0cd69856b75b49487b20e8d2f759d' 
  AND token = '3VCUiAy6ZzsuogzBjEvSwTnD08SNYUipx8d8nxk9MUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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