SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d02e2e4e1727fb2989f65bd38b58d3b3a5af0fda20373f549fb19237b3dca79' 
  AND token = 'I0GGbFG7GxmxSQgbzmQaXLlqpx+fi7DhzA4vJFIkovw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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