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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fd999e19205e7e517df3b1a4cae51b7f0cd4cd658fcc51dd8dddf2e5d199e7b' 
  AND token = 'IeEGGLhbNal8Py+9+C/IO1rJyz12DtAemv+7y+QZjjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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