SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a5391c148fdfa5cf9502f9579db39b0e169a95a44390864b09e4ed800f6c737f' 
  AND token = '2+P0PVdalc8dibsyHTHogzOsTPlp1qi/HEi4KKJlzyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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