SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b2c11f4ca82b81c76473282ae2a315e718e397618d3fcb3ba460274a6505146' 
  AND token = 'qC0FmvMo/SVmI8Du4w+e4ytlaE8o4w4+xcOJQnSWV9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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