SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3a414da876d29575ffec26cdd6fd76d1207381b97aa0dc184a1e548b3c6a973' 
  AND token = 'x9VLCqGcXcXigmC6mBPR7H4jjnQoq6+Fm2NVcLU8zJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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