SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9e08218c2d29546f29f4d3d46cb52cd2663ca6a75e97b04e7758fbc35b4e40d' 
  AND token = 'eXkrcCSWJBmTjRBU4uI61HXQvnO4JqslPZzDdGh22pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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