SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e74963909936d99beb38a20b2a55cd8f91ea40bcf8a9cec533a1c6d0fe64e98c' 
  AND token = 'AqhkeHdKhPPvc0FweXfhtNLTyNaEJYse6bOQdqys2uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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