SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2e9357d2d859a093eb6a6ef6bc7b0d4035d6d33f30476c48b8d61b22dd3159f' 
  AND token = '/WopuvSDKP4lwpsjSYPBOD/yD6zIS0yqVUihR9ZNjKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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