SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6be5607ef610e6a413c2441381ce3074740ecea52414c1b7252198cbc81c7392' 
  AND token = '5QiEWys5R7JIfO3YA0oatXGt1ahulxEWgtCXgyKJ3rI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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