SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1345515764ac78d38eef7a73b6b08177025014fd4cef8491125d2c39db3e49fb' 
  AND token = 'sa9TUq9mKVr43wmtb2+8M7o+vJ0BykCjOGx2ehiqTLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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