SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26d143c1ff034105a103aaf46da5bb36a7899df7f84931c624952f476f5dbb8d' 
  AND token = 'O+cQAstwyRxkt9B1gfMC8/kYRaz174CJsqGlv5ZQ4S8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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