SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea5682aea06d13a8f4eac9cc56048706ddd906e843a695056668e8261e90b75a' 
  AND token = 'TD6kJY09zGXYhfFDVljxWjDu3o9ZIwELh9O8uT6GDRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}