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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c6c490394a1568e6bb2aee9bfe8d7a3bd932d9efbb1a1fd720025d12fc62879' 
  AND token = 'QnfjQQIZF2l6KWF1qUJbWjes7OolRAB7cpL9N+eJEug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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