SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1907db1cc3746e90e808c017cb8f51545c53ffa3f5a8a6e066692c262e8781eb' 
  AND token = 'TYg8veXqw1nlVyzXLiaH+XFJp+DZGw+AF71/uYiyhmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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